The present invention relates to a safety engine load sensing system and more particularly to a system for use with gasoline powered, automatic transmission equipped vehicles for responding to unexpected load or acceleration of the engine and certain other potentially hazardous situations. During recent years there has been a spate of disturbing reports of vehicles going out of control as a result of the unexpected acceleration of the engine and causing injury to persons and damage to the vehicle and other property.
This particular problem does not appear to be limited to one make or model of automobile. In fact, while certain specific automobiles have received much of the notoriety associated with this problem, the fact appears to be that no modern gasoline powered vehicle equipped with an automatic transmission is totally immune to the problem.
The manufacturers of automobiles faced with this problem have apparently not been able conclusively to identify the cause of the difficulty. One common theory, but by no means the only one, is that the operator is at fault, perhaps stepping down on the accelerator pedal believing it to be the brake pedal. As a result, efforts to deal with it have been largely limited to the addition or modification of a linkage or mechanism to avoid the error just mentioned. However, even with the installation of safety devices the problem continues to exist and manufacturers of the automobiles appear to be stymied as to how to tackle the problem.
In U.S. Pat. Nos. 4,294,327 and 4,369,745 to Howard are shown safety devices primarily for use with riding lawn mowers to disable the engine in the event either the tractor transmission or the power takeoff is engaged, and prevent continued operation if either the transmission or power takeoff is engaged and the operator falls from or otherwise leaves the seat. The teachings of these patents are not applicable to the problem of unexpected acceleration in vehicles of the type to which this invention pertains.